1. Field of the Invention
The present invention relates to a process for producing a styrenic polymer. More particularly it pertains to a process for efficiently producing a styrenic polymer in which the stereochemical structure of the main polymer chain is of high degree of syndiotactic configuration.
2. Description of Relates Art
Styrenic polymers having a stereostructure of atactic or isotactic configuration have heretofore been well known, but there have recently been developed styrenic polymers having a stereostructure of predominant syndiotactic configuration, one of which, for example, is disclosed in Japanese Patent Application Laid-Open No. 187708/1987.
The styrenic polymer having syndiotactic configuration has heretofore been produced by batchwise or continuous system by the use of a tank type reactor equipped with agitating blades or the like, where the reaction heat generated through polymerization reaction and agitation heat are removed by cooling the reactor with a jacket fitted thereto.
Specifically, the styrenic polymer with syndiotactic configuration has a polymerization reaction heat of 160 kcal/kg, to which is added the agitation heat generated through the agitation in the polymerization reaction in the case of commercial operation of the reaction system. Here, the reaction heat and agitation heat are responsible for the trouble which hinders the proceeding of polymerization reaction such as agglomeration of the resultant polymer and adhesion of the polymer to the inside wall of the reactor. Consequently, the polymerization reactor is limited with respect to its capacity in the production of syndiotactic styrenic polymer insofar as the reactor equipped with a cooling jacket is employed for removing the reaction heat with agitation heat. Thus in the scale-up of the reactor for the purpose of enhancing the productivity of syndiotactic styrenic polymer, the removal of heat from inside of the reactor is an indispensable subject of utmost importance.
Under such circumstances facing the aforestated difficulty, intensive research and investigation were concentrated by the present inventors on the development of a continuous process for efficiently producing a styrenic polymer having a syndiotactic configuration, which process is capable of preventing the scaling of the polymer on the inside wall of the reactor as well as agglomeration thereof and at the same time, eliminating the problem of removing polymerzation reaction heat along with agitation heat in polymerization reaction and thereby efficiently operating the production plant.
As a result, it has been found by the present inventors that the aforesaid problems can be solved by the control of reaction temperature which takes advantage of the polymerization reaction heat in the reactor for the latent heat of vaporization for styrenic monomer. The present invention has been accomplished on the basis of the above-mentioned finding and information.